Conventionally, as a liquid crystal display, there has been used a liquid crystal display in TN mode in which a liquid crystal having a positive dielectric anisotropy is twisted aligned between substrates mutually facing to each other. However, in TN mode, when black view is displayed, optical leakage resulting from birefringence caused by liquid crystal molecule near a substrate made it difficult to obtain perfect display of black color owing to driving characteristics thereof. On the other hand, in a liquid crystal display in IPS mode, since liquid crystal molecule has almost parallel and homogeneous alignment to a substrate surface in non-driven state, light passes through the liquid crystal layer, without giving almost any change to a polarization plane, and as a result, arrangement of polarizing plates on upper and lower sides of the substrate enables almost perfect black view in non-driven state.
Although almost perfect black view may be realized in normal direction to a panel in IPS mode, when a panel is observed in oblique direction, inevitable optical leakage occurs caused by characteristics of a polarizing plate in a direction shifted from an optical axis of the polarizing plates placed on upper and lower sides of the liquid crystal cell, as a result, leading to a problem of narrowing of a viewing angle. That is, in a polarizing plate using a triacetyl cellulose (TAC) film that has been generally used as a protective film, there has remained a problem that a viewing angle is narrowed due to birefringence that the TAC film has.
In order to solve this problem, there has been used a polarizing plate that is compensated a geometric axis shift of a polarizing plate generated when observed in an oblique direction by a retardation film (see, for example, JP-A No. 4-305602 and JP-A No. 4-371903). The retardation film has been used as a protective film for a polarizer in the polarizing plate described in the published Patent Applications. With the retardation film described in the published Patent Applications, however, it is difficult to achieve a sufficiently wide viewing angle in IPS mode liquid crystal display.